The invention refers to a cooler for use as a heat sink for electrical components.
Coolers of this type, which consist of a number of plies or layers arranged superimposed in a stack and are suited for use as heat sinks for electrical or electronic components, circuits or modules, are principally known. In this respect, the use of metal layers that are connected with each other by means of DCB (direct copper bonding) technology is also known (IBMTDB, 1993, vol. 36, no. 11, pp. 291-293; IBMTDB, 1992, vol. 35, no. 4A, pp. 378-379.)
In addition, a cooler has already been proposed consisting of a number of cooler layers that form a three-dimensional micro cooler structure by means of corresponding structuring, i.e. a cooler structure that can be flowed through in three spatial axes extending vertically to each other (not previously published DE 197 10 783.4). In practice, it has been proven that the cooling capacity of such a cooler can not be increased despite an increase in the number of cooling layers, i.e. those cooling layers that are at a greater distance from the at least one cooling surface no longer contribute, or contribute only insignificantly, to the cooling effect.
Attempts have been made to overcome this disadvantage by having the cooling channels of a multi-layer cooler follow one another in a cascade and be flowed through by the coolant in the reverse flow. This results, however, in very long flow routes and therefore a higher flow resistance for the coolant through the cooler.
The purpose of the invention is to provide a cooler that enables an improved cooling capacity.
In order to solve this problem, a cooler for use as a heat sink for electrical or electronic components is disclosed. The cooler according to the invention can be manufactured easily and cheaply from several cooler layers stacked superimposed and connected with each other by means of a suitable method such as soldering, active soldering or DCB (direct copper bonding) technique etc.
According to one aspect of the invention, appropriate structuring of the first and/or second layer accomplishes that even with a number of layers, the coolant, which at first is flowing at the intake in areas of the cooler structure at a greater distance from the at least one cooling surface or at least a considerable portion of the coolant, is directed to or in the vicinity of the cooling surface and there contributes to or supplies the cooling effect.
According to another aspect of the invention, a reduction of the overall flow resistance is obtained by enlargement of the passages at the intersections of the structures. At the same differential pressure on the cooler, a higher coolant flow rate and therefore an increase in the cooling effect is achieved.